This study was designed to evaluate the efficacy of a new investigational rescue inhaler device for children and adolescents (ages 4-17) with severe asthma. This dry powder inhaler features both a broncodilator (albuterol sulfate) + corticosteroid, and will be compared to a typical rescue inhaler which only contains the broncodilator. There will be no cost to any participants in the trial. No medical insurance is required, legal status will not be asked for, and compensation may be provided |